Average recoil ranges of 64Cu and 196Au produced by protons of 20–85 MeV energy in 65Cu and 197Au

Abstract

Thick-target recoil experiments were performed to study (p,pn) reactions induced in 65Cu and 197Au in the energy range of 20–85 MeV and the average ranges projected in the forward, backward, and perpendicular directions were determined. Recoil parameters have been calculated to show approximately the amount of energy transfer and their energy dependence. The average range results have been compared with statistical theory, cascade–evaporation (85 MeV only), and inelastic scattering model calculations. The statistical calculations show reasonable agreement up to 30–40 MeV. However, the calculated projected range values, based on the cascade–evaporation and the inelastic scattering models, are consistently lower than the measured values. The analyses of the projected range values support the prevalent view that at low energies (~ 30–35 MeV), the compound nucleus mechanism is predominant and at higher energies, the direct interaction mechanism makes a major contribution.